<template>
  <div :class="{ show: show }" class="header-search">
    <svg-icon
      class-name="search-icon"
      icon-class="search"
      @click.stop="click"
    />
    <el-select
      ref="headerSearchSelect"
      v-model="search"
      :remote-method="querySearch"
      filterable
      default-first-option
      remote
      placeholder="Search"
      class="header-search-select"
      @change="change"
    >
      <el-option
        v-for="item in options"
        :key="item.path"
        :value="item"
        :label="item.title.join(' > ')"
      >
      </el-option>
    </el-select>
  </div>
</template>

<script>
import Fuse from "fuse.js";
import path from "path";
import i18n from "@/locale";

export default {
  name: "HeaderSearch",
  data() {
    return {
      search: "",
      options: [],
      searchPool: [],
      show: false,
      fuse: undefined,
    };
  },
  computed: {
    routes() {
      return this.$store.getters.asyncRoutes;
    },
    lang() {
      return this.$store.getters.language;
    },
    supportPinyinSearch() {
      return this.$store.state.settings.supportPinyinSearch;
    },
  },
  watch: {
    lang() {
      this.searchPool = this.generateRoutes(this.routes);
    },
    routes() {
      this.searchPool = this.generateRoutes(this.routes);
    },
    searchPool(list) {
      if (this.lang === "zh" && this.supportPinyinSearch) {
        this.addPinyinField(list);
      }
      this.initFuse(list);
    },
    show(value) {
      if (value) {
        document.body.addEventListener("click", this.close);
      } else {
        document.body.removeEventListener("click", this.close);
      }
    },
  },
  mounted() {
    this.searchPool = this.generateRoutes(this.routes);
  },
  methods: {
    async addPinyinField(list) {
      const { default: pinyin } = await import("pinyin");
      if (Array.isArray(list)) {
        list.forEach((element) => {
          const title = element.title;
          if (Array.isArray(title)) {
            title.forEach((v) => {
              v = pinyin(v, { style: pinyin.STYLE_NORMAL }).join("");
              element.pinyinTitle = v;
            });
          }
        });
        return list;
      }
    },
    click() {
      this.show = !this.show;
      if (this.show) {
        this.$refs.headerSearchSelect && this.$refs.headerSearchSelect.focus();
      }
    },
    close() {
      this.$refs.headerSearchSelect && this.$refs.headerSearchSelect.blur();
      this.options = [];
      this.show = false;
    },
    change(val) {
      this.$router.push(val.path);
      this.search = "";
      this.options = [];
      this.$nextTick(() => {
        this.show = false;
      });
    },
    initFuse(list) {
      this.fuse = new Fuse(list, {
        shouldSort: true,
        threshold: 0.4,
        location: 0,
        distance: 100,
        maxPatternLength: 32,
        minMatchCharLength: 1,
        keys: [
          {
            name: "title",
            weight: 0.7,
          },
          {
            name: "pinyinTitle",
            weight: 0.3,
          },
          {
            name: "path",
            weight: 0.3,
          },
        ],
      });
    },
    generateRoutes(routes, basePath = "/", prefixTitle = []) {
      let res = [];
      for (const router of routes) {
        // skip hidden router
        if (router.hidden) {
          continue;
        }
        const data = {
          path: path.resolve(basePath, router.path),
          title: [...prefixTitle],
        };
        if (router.meta && router.meta.title) {
          // generate internationalized title
          let i18ntitle = router.meta.title;
          if (/^[a-z1-9\-]*$/gi.test(i18ntitle)) {
            i18ntitle = i18n.t(`route.${i18ntitle}`);
          }
          data.title = [...data.title, i18ntitle];
          if (router.redirect !== "noRedirect") {
            // only push the routes with title
            // special case: need to exclude parent router without redirect
            res.push(data);
          }
        }
        // recursive child routes
        if (router.children) {
          const tempRoutes = this.generateRoutes(
            router.children,
            data.path,
            data.title
          );
          if (tempRoutes.length >= 1) {
            res = [...res, ...tempRoutes];
          }
        }
      }
      return res;
    },
    querySearch(query) {
      if (query !== "") {
        const fuseres = this.fuse.search(query);
        this.options = fuseres.map((item) => item.item);
      } else {
        this.options = [];
      }
    },
  },
};
</script>

<style lang="scss" scoped>
.header-search {
  font-size: 0 !important;
  .search-icon {
    cursor: pointer;
    font-size: 18px;
    vertical-align: middle;
  }
  .header-search-select {
    font-size: 18px;
    transition: width 0.2s;
    width: 0;
    overflow: hidden;
    background: transparent;
    border-radius: 0;
    display: inline-block;
    vertical-align: middle;

    ::v-deep .el-input__inner {
      border-radius: 0;
      border: 0;
      padding-left: 0;
      padding-right: 0;
      box-shadow: none !important;
      border-bottom: 1px solid #d9d9d9;
      vertical-align: middle;
    }
  }
  &.show {
    .header-search-select {
      width: 210px;
      margin-left: 10px;
    }
  }
}
</style>